The pattern of DNA replication in the chromosomes of Puschkinia libanotica

  title={The pattern of DNA replication in the chromosomes of Puschkinia libanotica},
  author={Peter W. Barlow and Canio G. Vosa},
The uptake of H3-thymidine into the chromosomes of Puschkinia libanotica has been studied in plants possessing or lacking a heterochromatic B chromosome. The pattern of H3-thymidine uptake by the A chromosomes at the end of the S phase is similar in plants of both genotypes. Regions around the centromere take up more H3-thymidine at the end of S than do more distal regions. The rate of uptake into the heterochromatin of the B chromosome increases towards the end of S, but there is no evidence… 

The effect of supernumerary chromosomes on meiosis in Puschkinia libanotica (Liliaceae)

The pattern of chiasma distribution along each of the five A bivalents was related to the DNA labelling pattern of mitotic chromosomes, and Regions that showed heavy labelling at the end of the DNA synthetic phase had fewer chiasmata than lightly labelled regions.

B chromosomes of Puschkinia libanotica are characterized by a reduced level of euchromatic histone H3 methylation marks

The results indicate that the less-transcriptionally active Bs are not marked by an enriched level of heterochromatic histone marks, but rather by a low level of euchromatin-associated histone modifications.

Late labelled regions in relation to Q- and C-bands in chromosomes of Lilium longiflorum and L. pardalinum

Bright Q-bands are apparently not consistently late replicating in Lilium, as they are in mammals, and they may therefore represent a different category of chromosomal substructure.

C-banded karyotypes in theScilla hohenackeri group,S. persica, andPuschkinia (Liliaceae)

Quantitatively evaluated C-banding karyograms and further observations on karyotype structure are presented for Scilla persica, 7 species of the Scilla hohenackeri group, and Puschkinia scilloides, finding very diverse and species-specific banding patterns are found.



The chromosomes of Puschkinia libanotica during mitosis

Microdensitometry of metaphase chromosomes shows that the segment of the B chromosome that is heterochromatic during interphase has no more DNA per unit volume than any of the euchromatic A chromosomes.

Rate of DNA replication in the DNA synthetic period of the barley chromosomes

Evidence suggests that the replication of chromosomal DNA in the present material does not proceed in a continuous time sequence, and the interrelationships among chromosome structure in its cytological expression, replication -pattern and -time of chromosomes, and regulating mechanisms of DNA replication are discussed.

Asynchronous DNA Replication of Sex-Chromatin in Interphase Nuclei of Male Sorrel Plant, Rumex acetosa

The problem of replication in a heteropycnotic sex-chromatin in interphase nuclei has been broached, at least, in so far as DNA is concerned, in somatic nuclei of the male sorrel, Rumex acetosa.

Differential Uptake of Tritiated Thymidine into Hetero- and Euchromatin in Melanoplus and Secale

In rye the asynchrony of synthesis occurs within each chromosome, and in this species during early prophase of meiosis the sex chromosome forms a heterochromatic block large enough to be resolved in tritium autoradiographs.

Late DNA Synthesis in Heterochromatin

It seems to be a rule of chromosome replication that heterochromatin synthesizes its DNA at a later stage than the rest of the chromosome.